There was a school attack in China today. 22 injuries, 2 serious. The attacker was armed with a knife.
http://www.bbc.co.uk/news/world-asia-china-20723910
In China, it was an attack because the crazy person was armed with a knife. In the US, it was a massacre because the crazy person was armed with guns. It is pretty hard to argue that US gun laws don't make these events bloodier than they have to be.
It may be unpopular, but I'll say it... guns don't kill people, people kill people.
Guns just make it easier and increase the body count.